Texas Instruments ADS122U04IRTET

Overview

ADS122U04IRTET from Texas Instruments is a 24-bit, 4-channel, 2-kSPS delta-sigma ADC with integrated UART interface, programmable gain amplifier (PGA), dual matched current sources (10 µA to 1.5 mA), internal 2.048-V reference (5 ppm/°C drift), and precision temperature sensor (±0.5°C). It supports two differential or four single-ended inputs and operates from 2.3 V to 5.5 V, targeting thermocouple, RTD, and bridge sensor signal conditioning in industrial temperature monitoring systems.

For engineers reviewing the ADS122U04IRTET datasheet, ADS122U04IRTET pinout, ADS122U04IRTET application, or ADS122U04IRTET equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated WQFN-16 pin functions, confirmed alternative parts with functional differences, and supply-ready availability details - all grounded in TI's SBAS752B production data sheet.

Technical Context

The ADS122U04IRTET implements a 24-bit delta-sigma modulator with single-cycle settling digital filter supporting simultaneous 50-Hz and 60-Hz rejection at 20 SPS. Its PGA provides gains from 1 to 128, enabling high-resolution measurement of low-level sensor outputs such as K-type thermocouples and 100-Ω RTDs.

It integrates a UART-compatible 2-wire serial interface (up to 120 kBaud) with auto-baud detection, three GPIOs (including DRDY), internal oscillator (1.024 MHz normal / 2.048 MHz turbo mode), and cold-junction compensation logic - eliminating external timing, isolation, and signal-conditioning components in isolated analog input modules.

Key Specifications

Pinout & Package

ADS122U04IRTET is packaged in a 3.0-mm × 3.0-mm, 0.75-mm height, 16-pin WQFN (RTE) with exposed thermal pad connected to AVSS.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision delta-sigma ADC applications.

Compared with ADS122U04IRTET, ADS124S08IPW offers more channels and diagnostics but lacks UART simplification for isolation, while AD7124-4BRUZ trades UART convenience for SPI flexibility and slightly relaxed linearity - both require external isolation solutions absent in the ADS122U04IRTET's native UART architecture.

Availability

ADS122U04IRTET is available at Aetrix Electronics and suitable for industrial temperature transmitters, PLC analog input modules, and medical patient monitors requiring stable component supply across extended product lifecycles.

Supply support for ADS122U04IRTET includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision data acquisition and industrial signal chain solutions.

The ADS122U04IRTET belongs to TI's high-precision delta-sigma ADC portfolio, designed specifically for simplified, isolated sensor front-ends in harsh industrial and medical environments where UART interface, low power, and integrated compensation reduce system complexity.

FAQ

What is the maximum data rate supported by the ADS122U04IRTET?

The ADS122U04IRTET supports up to 2000 samples per second (2 kSPS) in turbo mode. At this rate, the device maintains 24-bit no-missing-codes resolution and delivers effective resolution of approximately 18 bits. The trade-off is reduced noise rejection capability compared to lower rates like 20 SPS, where simultaneous 50-Hz and 60-Hz rejection is guaranteed. For ADS122U04IRTET implementations requiring high-speed thermal event capture - such as rapid oven ramp monitoring - turbo mode provides deterministic latency under 500 µs per conversion.

Does the ADS122U04IRTET include an internal voltage reference?

Yes, the ADS122U04IRTET integrates a precision 2.048-V internal voltage reference with typical drift of 5 ppm/°C and initial accuracy of ±0.25% (WQFN package). This reference can be used directly for ratiometric measurements or bypassed in favor of an external reference applied across REFP and REFN. The internal reference eliminates the need for an external reference IC in most thermocouple and RTD applications, reducing BOM count and layout area. For ADS122U04IRTET users implementing cold-junction compensation, the internal reference ensures stable scaling of the on-die temperature sensor output.

How does the UART interface of the ADS122U04IRTET simplify isolation in industrial systems?

The ADS122U04IRTET's 2-wire UART interface reduces digital isolation requirements from four signals (SPI: CLK, MOSI, MISO, CS) to just two (TX and RX), cutting isolator cost and PCB footprint by ~40%. Its auto-baud-rate detection eliminates the need for pre-negotiated communication settings, and its 8-N-1 format ensures compatibility with standard microcontroller UART peripherals. In ADS122U04IRTET-based PLC modules, this architecture enables single-channel digital isolators (e.g., Si8602) instead of multi-channel SPI isolators, improving reliability and easing EMI filtering.

Can the ADS122U04IRTET measure thermocouple signals directly?

Yes, the ADS122U04IRTET is explicitly designed for direct K-type thermocouple interfacing. It combines a low-noise PGA (gain up to 128), internal cold-junction compensation via its ±0.5°C accurate on-die temperature sensor, and programmable burn-out current sources (10 µA) to detect open thermocouple faults. When configured with AIN0/AIN1 as differential inputs and internal reference enabled, ADS122U04IRTET delivers end-to-end thermocouple measurement accuracy better than ±1.5°C over –40°C to +125°C ambient - without external op-amps, references, or compensation ICs.

What package options are available for the ADS122U04IRTET?

The ADS122U04IRTET is offered exclusively in the 3.0-mm × 3.0-mm, 0.75-mm height, 16-pin WQFN (RTE) package with wettable flanks and an exposed thermal pad. This package is RoHS-compliant, halogen-free, and optimized for automated optical inspection (AOI) and reflow soldering. The "IRTET" suffix in ADS122U04IRTET explicitly denotes the WQFN-16 variant; TI does not list a TSSOP version under this orderable part number. The thermal pad must be soldered to AVSS for proper thermal performance and noise immunity in ADS122U04IRTET designs.